Phl controller described a TCAS RA event when traffic being vectored for the ILS 27R was issued a de...

Attributes
ACN	944345
Time
Date	201104
Local Time Of Day	1801-2400
Place
Locale Reference	PHL.TRACON
State Reference	PA
Aircraft 1
Make Model Name	EMB ERJ 170/175 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Cruise
Route In Use	None
Flight Plan	VFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Procedural Published Material / Policy

Narrative:

Phl west flow landing 27R. The E170 flight was on a vector southbound toward the localizer for 27R and was descended to 2;100 and left the bravo airspace; VFR traffic was at 1;900 outside the bravo airspace northbound. I called the VFR traffic to the E170; pilot responded looking. The E170 responded to an TCAS-RA; after the RA the E170 flight descended back down to 2;100 ft and was cleared for the approach. I descended the E170 to 2;100 because I was planning on a turn at the approach gate (final approach fix altitude is 2;100) and I wanted the flight to be below the glide slope for the ILS approach. To prevent the recurrence of this event; traffic should not be descended below the bravo airspace. The bottom altitude of the shelf of the bravo airspace in the area the E170 was in is 3;000.

Original NASA ASRS Text

Title: PHL Controller described a TCAS RA event when traffic being vectored for the ILS 27R was issued a descent below the Class B and triggered an RA; the reporter suggesting Class B revisions to accommodate this type of circumstance.

Narrative: PHL West flow landing 27R. The E170 flight was on a vector southbound toward the localizer for 27R and was descended to 2;100 and left the Bravo airspace; VFR traffic was at 1;900 outside the Bravo airspace northbound. I called the VFR traffic to the E170; pilot responded looking. The E170 responded to an TCAS-RA; after the RA the E170 flight descended back down to 2;100 FT and was cleared for the approach. I descended the E170 to 2;100 because I was planning on a turn at the approach gate (final approach fix altitude is 2;100) and I wanted the flight to be below the glide slope for the ILS approach. To prevent the recurrence of this event; traffic should not be descended below the Bravo airspace. The bottom altitude of the shelf of the Bravo airspace in the area the E170 was in is 3;000.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Phl controller described a TCAS RA event when traffic being vectored for the ILS 27R was issued a descent below the class B and triggered an RA; the reporter suggesting class B revisions to accommodate this type of circumstance.